The present invention relates to a novel flame retardant heat insulating composition and a method for preparing the same. More particularly, it relates to a fiberfil composition for a flame retardant heat insulating material of cellulosic fiberfil type which is useful in a flame retardant heat insulating mat, a flame retardant sound absorbing fiber and a flame retardant sound absorbing mat.
Since the oil crisis, energy and resources saving policyhas accelerated a general trend to improve the heat insulating property of buildings and houses, which in turn has led to various studies to improve the heat insulating property of materials, standardize steps for installing the insulation, and reduce the installation cost. It is particularly desired to improve the heat insulating property of glass wool and rock wool fiberfil mats used as conventional insulating materials, as well as to reduce the working costs and to improve workability by simplifying the steps for installing the insulation. In order to obviate these defects, it has been suggested to use a cellulose heat insulating fiberfil material of cellulose fibers, which is made of wood pulp and made flame retardant by treating it with borate or boric acid. The pulp has been conventionally used in the United States and Canada as an insulating material for buildings and houses. This flame retardant heat insulating material of cellulose fibers is injected or sprayed for insulation, and the installation and work efficiency are 5 to 10 times greater than the heat insulating glass wool and rock wool mats. The installation cost can also be reduced considerably. Moreover, the flame-retardant heat insulating material of cellulose fibers can be easily installed in buildings already existing as well as the buildings to be newly built; and the insulation can be extended to every and entire parts of a building, improving the insulating property greatly.
However, the flame retardant heat insulating material of cellulose fibers of the prior art has a disadvantage in that borate or boric is used in order to make the material flame retardant, and the content thereof is quite high at 15 to 25%. The inclusion of such chemicals renders the material to be highly water-absorbing. The material absorbs more moisture in the course of time to result in decreased bulk volume of the heat insulating fiber. The bulk of insulating material which has shrink on ageing on settling causes voids at various insulated parts of a house or building, and thus significantly decreases the heat insulating property. The hydroscopic nature of the insulating fiber itself impairs the insulating property of the material. In other words, the insulating material of cellulose fibers of the prior art is defective in that due to its moisture absorbing nature, the insulating property deteriorates not only as the material but also as the insulating material when installed.